Diesel detergent without a low molecular weight penalty

ABSTRACT

The composition of the present invention related to a quaternary ammonium salt detergent and the use of such quaternary ammonium salt detergents in a fuel composition to reduce diesel injector deposits and remove or clean up existing deposits on the diesel injectors.

BACKGROUND OF THE INVENTION

The composition of the present invention is related to a quaternaryammonium salt detergent and the use of such quaternary ammonium saltdetergents in a fuel composition to reduce diesel injector deposits andremove or clean up existing deposits on the diesel injectors.

It is well known that liquid fuel contains components that can degradeduring engine operation and form deposits. These deposits can lead toincomplete combustion of the fuel resulting in higher emission andpoorer fuel economy. Fuel additives, such as detergents, are well knownadditives in liquid fuels to help with control or minimize depositformation. As the dynamics and mechanics of an engine continual advance,the requirements of the fuel must evolve to keep up with these engineadvancements. For example, today's engines have injector system thathave smaller tolerances and operate at higher pressure to enhance fuelspray to the compression or combustion chamber. Deposit prevention anddeposit reduction in these new engines has become critical to optimaloperation of today's engines. Advancements in fuel additive technology,such as detergents, have enabled the fuel to keep up with these engineadvancements. Therefore there is a need for detergent capable ofproviding acceptable performance in a liquid fuel to promote optimaloperation of today's engines.

U.S. Pat. No. 5,000,792 discloses polyesteramine detergent obtainable byreacting 2 parts of polyhydroxycarboxylic acids with 1 part ofdialkylenetriamine.

U.S. Pat. No. 4,171,959 discloses a motor fuel composition containingquaternary ammonium salts of a succinimide. The quaternary ammonium salthas a counterion of a halide, a sulphonate or a carboxylate.

U.S. Pat. No. 4,338,206 and U.S. Pat. No. 4,326,973 discloses fuelcompositions containing a quaternary ammonium salt of a succinimide,wherein the ammonium ion is heterocyclic aromatic (pyridinium ion).

U.S. Pat. No. 4,108,858 discloses a fuel or lubricating oil compositioncontaining a C2 to C4 polyolefin with a Mw of 800 to 1400 salted with apyridinium salt.

U.S. Pat. No. 5,254,138 discloses a fuel composition containing areaction product of a polyalkyl succinic anhydride with a polyaminohydroxyalkyl quaternary ammonium salt.

U.S. Pat. No. 4,056,531 discloses a lubricating oil or fuel containing aquaternary ammonium salt of a hydrocarbon with a Mw of 350 to 3000bonded to triethylenediamine. The quaternary ammonium salt counterion isselected from halides, phosphates, alkylphosphates, dialkylphosphates,borates, alkylborates, nitrites, nitrates, carbonates, bicarbonates,alkanoates, and O,O-dialkyldihtiophosphates.

U.S. Pat. No. 4,248,719 discloses a fuel or lubricating oil containing aquaternary ammonium salt of a succinimide with a monocarboxylic acidester. U.S. Pat. No. 4,248,719 does not teach, suggest or otherwisedisclose low sulphur fuels, presence of fluidisers etc. Example 1teaches polyisobutylene succinimide with DMAPA as the amine. Thesuccinimide is then reacted with a salicylate.

U.S. Pat. No. 4,253,980 and U.S. Pat. No. 4,306,070 disclose a fuelcomposition containing a quaternary ammonium salt of an ester-lactone.

U.S. Pat. No. 3,778,371 discloses a lubricating oil or fuel containing aquaternary ammonium salt of a hydrocarbon with a Mw of 350 to 3000; andthe remaining groups to the quaternary nitrogen are selected from thegroup of C1 to C20 alkyl, C2 to C8 hydroxyalkyl, C2 to C20 alkenyl orcyclic groups.

US 2011/0302828 to Fang et al., published Dec. 15, 2011 discloses adiesel fuel composition containing diesel fuel additive having a numberaverage molecular weight of 500 to 10,000, wherein less than 25 wt % ofthe additive has a molecular weight of 400 or less.

The present invention, therefore, promotes optimal engine operation,that is, increased fuel economy, better vehicle drivability, reducedemissions and less engine maintenance by reducing, minimizing andcontrolling deposit formation.

SUMMARY OF THE INVENTION

The present invention further provides a method for fueling an internalcombustion engine, comprising:

A. supplying to said engine:

-   -   I. a fuel which is liquid at room temperature; and    -   II. quaternary ammonium salt comprising the reaction product of:        -   (a) a compound comprising (i) at least one tertiary amino            group, and (ii) a hydrocarbyl-substituent having a number            average molecular weight of from about 100 to about 500; and        -   (b) a quaternizing agent suitable for converting the            tertiary amino group of (a)(i) to a quaternary nitrogen,

wherein the quaternizing agent is selected from the group consisting ofdialkyl sulfates, benzyl halides, hydrocarbyl substituted carbonates;hydrocarbyl epoxides, hydrocarbyl epoxides in combination with an acid,or mixtures thereof.

The present invention additionally provides for a composition comprisinga quaternary ammonium salt, wherein the quaternary ammonium saltcomprises the reaction product of:

-   -   (a) a compound comprising (i) at least one tertiary amino group,        and    -   (ii) a hydrocarbyl-substituent having a number average molecular        weight of from about 100 to about 500; and    -   (b) a quaternizing agent suitable for converting the tertiary        amino group of (a)(i) to a quaternary nitrogen.

The above compositions can additionally comprise a quaternary ammoniumsalt, wherein the quaternary ammonium salt comprises the reactionproduct of:

-   -   (a) a compound comprising (i) at least one tertiary amino group,        and    -   (ii) a hydrocarbyl-substituent derived from a hydrocarbon having        a number average molecular weight of from about 500 to about        5000; and    -   (b) a quaternizing agent suitable for converting the tertiary        amino group of compound (a) to a quaternary nitrogen

DETAILED DESCRIPTION OF THE INVENTION

Various preferred features and embodiments will be described below byway of non-limiting illustration.

This invention involves a quaternary ammonium salt, a fuel compositionthat includes the quaternary ammonium salt, and a method of operating aninternal combustion engine with the fuel composition. The compositionsand methods of the present invention minimize, reduce and controldeposit formation in the engine, which reduces fuel consumption,promotes drivability, vehicle maintenance, and reduces emissions whichenables optimal engine operation.

Fuel

The composition of the present invention can comprise a fuel which isliquid at room temperature and is useful in fueling an engine. The fuelis normally a liquid at ambient conditions e.g., room temperature (20 to30° C.). The fuel can be a hydrocarbon fuel, a nonhydrocarbon fuel, or amixture thereof. The hydrocarbon fuel can be a petroleum distillate toinclude a gasoline as defined by ASTM specification D4814 or a dieselfuel as defined by ASTM specification D975. In an embodiment of theinvention the fuel is a gasoline, and in other embodiments the fuel is aleaded gasoline, or a nonleaded gasoline. In another embodiment of thisinvention the fuel is a diesel fuel. The hydrocarbon fuel can be ahydrocarbon prepared by a gas to liquid process to include for examplehydrocarbons prepared by a process such as the Fischer-Tropsch process.The nonhydrocarbon fuel can be an oxygen containing composition, oftenreferred to as an oxygenate, to include an alcohol, an ether, a ketone,an ester of a carboxylic acid, a nitroalkane, or a mixture thereof. Thenonhydrocarbon fuel can include for example methanol, ethanol, methylt-butyl ether, methyl ethyl ketone, transesterified oils and/or fatsfrom plants and animals such as rapeseed methyl ester and soybean methylester, and nitromethane. Mixtures of hydrocarbon and nonhydrocarbonfuels can include for example gasoline and methanol and/or ethanol,diesel fuel and ethanol, and diesel fuel and a transesterified plant oilsuch as rapeseed methyl ester. In an embodiment of the invention theliquid fuel is an emulsion of water in a hydrocarbon fuel, anonhydrocarbon fuel, or a mixture thereof. In several embodiments ofthis invention the fuel can have a sulphur content on a weight basisthat is 5000 ppm or less, 1000 ppm or less, 300 ppm or less, 200 ppm orless, 30 ppm or less, or 10 ppm or less. In another embodiment the fuelcan have a sulphur content on a weight basis of 1 to 100 ppm. In oneembodiment the fuel contains about 0 ppm to about 1000 ppm, about 0 toabout 500 ppm, about 0 to about 100 ppm, about 0 to about 50 ppm, about0 to about 25 ppm, about 0 to about 10 ppm, or about 0 to 5 ppm ofalkali metals, alkaline earth metals, transition metals or mixturesthereof. In another embodiment the fuel contains 1 to 10 ppm by weightof alkali metals, alkaline earth metals, transition metals or mixturesthereof. It is well known in the art that a fuel containing alkalimetals, alkaline earth metals, transition metals or mixtures thereofhave a greater tendency to form deposits and therefore foul or plugcommon rail injectors. The fuel of the invention is present in a fuelcomposition in a major amount that is generally greater than 50 percentby weight, and in other embodiments is present at greater than 90percent by weight, greater than 95 percent by weight, greater than 99.5percent by weight, or greater than 99.8 percent by weight.

The Quaternary Ammonium Salt

The quaternary ammonium salts of the present invention include thereaction product of: (i) a compound comprising at least one tertiaryamino group and a hydrocarbyl-substituent derived from a hydrocarbonhaving a number average molecular weight of from about 100 to about 500,or from 100 to about 450, 150 to about 400, or 200 to about 350; and(ii) a quaternizing agent suitable for converting the tertiary aminogroup of compound (i) to a quaternary nitrogen.

The hydrocarbyl-substituent having a number average molecular weight offrom about 100 to about 500, or from 100 to about 450, 150 to about 400,or 200 to about 350 can be, for example, a polyolefin, a polyalkene, oran ester or polyester. Example quaternary ammonium salts comprising ahydrocarbyl-substituent can therefore include, for example, the reactionproduct of: (i) at least one compound which may include: (a) thecondensation product of a hydrocarbyl-substituted acylating agent and acompound having an oxygen or nitrogen atom capable of condensing theacylating agent where the condensation product has at least one tertiaryamino group; (b) a polyalkene-substituted amine having at least onetertiary amino group; and (c) a polyester that is the reaction productof a fatty carboxylic acid containing at least one hydroxyl group and acompound having an oxygen or nitrogen atom capable of condensing withsaid acid where said compound contains a tertiary amino group; and (ii)a quaternizing agent suitable for converting the tertiary amino groupcompound of (i) to a quaternary nitrogen.

The quaternary ammonium salts of the present invention also include thereaction product of: (i) a compound comprising at least one tertiaryamino group; and (ii) a quaternizing agent suitable for converting thetertiary amino group of compound (i) to a quaternary nitrogen.

Example quaternary ammonium salts can include, for example, the reactionproduct of: (i) at least one compound which may include: (d) a Mannichreaction product having at least one tertiary amino group, where theMannich reaction product is derived from a hydrocarbyl-substitutedphenol, an aldehyde, and an amine, (e) a non-quaternized amide and/orester detergent having a tertiary amine functionality; and (ii) aquaternizing agent suitable for converting the tertiary amino group ofcompound (i) to a quaternary nitrogen.

The quaternizing agent may include dialkyl sulfates, benzyl halides,hydrocarbyl substituted carbonates, and hydrocarbyl epoxides, any ofwhich may be used in combination with an acid.

The compounds of component (i)(a)-(i)(e), described in greater detailbelow, contain at least one tertiary amino group and include compoundsthat may be alkylated to contain at least one tertiary amino group afteran alkylation step.

Examples of quaternary ammonium salts and methods for preparing the sameare described in U.S. Pat. Nos. 4,253,980; 3,778,371; 4,171,959;4,326,973; 4,338,206; and 5,254,138.

The quaternary ammonium salts may be prepared in the presence of asolvent, which may or may not be removed once the reaction is complete.Suitable solvents include, but are not limited to, diluent oil,petroleum naphtha, and certain alcohols. In one embodiment, thesealcohols contain at least 2 carbon atoms, and in other embodiments atleast 4, at least 6 or at least 8 carbon atoms. In another embodiment,the solvent of the present invention contains 2 to 20 carbon atoms, 4 to16 carbon atoms, 6 to 12 carbon atoms, 8 to 10 carbon atoms, or just 8carbon atoms. These alcohols often have a 2-(C₁₋₄ alkyl) substituent,namely, methyl, ethyl, or any isomer of propyl or butyl. Examples ofsuitable alcohols include 2-propylheptanol, 2-methyldecanol,2-ethylpentanol, 2-ethylhexanol, 2-ethylnonanol, 2-propylheptanol,2-butylheptanol, 2-butyloctanol, isooctanol, dodecanol, cyclohexanol,methanol, ethanol, propan-1-ol, 2-methylpropan-2-ol,2-methylpropan-1-ol, butan-1-ol, butan-2-ol, pentanol and its isomers,and mixtures thereof. In one embodiment the solvent of the presentinvention is 2-ethylhexanol, 2-ethyl nonanol, 2-methylheptanol, orcombinations thereof. In one embodiment the solvent of the presentinvention includes 2-ethylhexanol.

Various embodiments of suitable quaternary ammonium salts are describedherein and the invention contemplates the use of any one of them orcombination thereof.

Succinimide Quaternary Ammonium Salts

In one embodiment the quaternary salt detergent comprises the reactionproduct of (i)(a) the condensation product of a hydrocarbyl-substitutedacylating agent and a compound having an oxygen or nitrogen atom capableof condensing with said acylating agent where the condensation producthas at least one tertiary amino group; and (ii) a quaternizing agentsuitable for converting the tertiary amino group of compound (i) to aquaternary nitrogen.

Hydrocarbyl substituted acylating agents useful in the present inventioninclude the reaction product of a short chain hydrocarbon, generally apolyolefin, with a monounsaturated carboxylic acid or derivativethereof.

Suitable monounsaturated carboxylic acids or derivatives thereofinclude: (i) α,β-monounsaturated C₄ to C₁₀ dicarboxylic acids, such asfumaric acid, itaconic acid, maleic acid; (ii) derivatives of (i), suchas anhydrides or C₁ to C₅ alcohol derived mono- or di-esters of (i);(iii) α,β-monounsaturated C₃ to C₁₀ monocarboxylic acids, such asacrylic acid and methacrylic acid; or (iv) derivatives of (iii), such asC₁ to C₅ alcohol derived esters of (iii).

The short chain hydrocarbon for use in preparing thehydrocarbyl-substituted acylating agents can have a number averagemolecular weight of from about 100 to about 500, or from 100 to about450, 150 to about 400, or 200 to about 350. Suitable hydrocarbonsinclude any compound containing an olefinic bond represented by thegeneral Formula I, shown here:

(R¹)(R²)C═C(R³)(CH(R⁴)(R⁵))   (I)

wherein each of R¹, R², R³, R⁴ and R⁵ is, independently, hydrogen or ahydrocarbon based group. In some embodiments at least one of R³, R⁴ orR⁵ is a hydrocarbon based group containing up to about 36 carbon atoms.

These short chain hydrocarbons, which may also be described aspolyolefins or olefin polymers, are reacted with the monounsaturatedcarboxylic acids and derivatives described above to form the hydrocarbylsubstituted acylating agents used to prepare the nitrogen-containingdetergent of the present invention. Suitable olefin polymers includepolymers comprising a major molar amount of C₂ to C₂₀, or C₂ to C₅mono-olefins. Such olefins include ethylene, propylene, butylene,isobutylene, pentene, octene-1, or styrene. The polymers may behomo-polymers, such as polyisobutylene, as well as copolymers of two ormore of such olefins. Suitable copolymers include copolymers of ethyleneand propylene, butylene and isobutylene, and propylene and isobutylene.Other suitable copolymers include those in which a minor molar amount ofthe copolymer monomers, e.g. 1 to 10 mole %, is a C₄ to C₁₈ di-olefin.Such copolymers include: a copolymer of isobutylene and butadiene; and acopolymer of ethylene, propylene and 1,4-hexadiene.

In one embodiment, at least one of the —R groups of Formula (I) shownabove is derived from polybutene, that is, polymers of C₄ olefins,including 1-butene, 2-butene and isobutylene. C₄ polymers includepolyisobutylene. In another embodiment, at least one of the —R groups ofFormula I is derived from ethylene-alpha olefin polymers, includingethylene-propylene-diene polymers. Examples of documents that describedethylene-alpha olefin copolymers and ethylene-lower olefin-dieneter-polymers include U.S. Pat. Nos. 3,598,738; 4,026,809; 4,032,700;4,137,185; 4,156,061; 4,320,019; 4,357,250; 4,658,078; 4,668,834;4,937,299; and 5,324,800.

In another embodiment, the olefinic bonds of Formula (I) arepredominantly vinylidene groups, represented by the following formula:

wherein each R is a hydrocarbyl group; which in some embodiments may be:

wherein R is a hydrocarbyl group.

In one embodiment, the vinylidene content of Formula (I) may comprise atleast 30 mole % vinylidene groups, at least 50 mole % vinylidene groups,or at least 70 mole % vinylidene groups. Such materials and methods ofpreparation are described in U.S. Pat. Nos. 5,071,919; 5,137,978;5,137,980; 5,286,823, 5,408,018, 6,562,913, 6,683,138, 7,037,999; andUnited States publications: 2004/0176552A1; 2005/0137363; and2006/0079652A1. Such products are commercially available from BASF,under the tradename GLISSOPAL™ and from Texas PetroChemical LP, underthe tradename TPC 1105™ and TPC 595™.

Methods of making hydrocarbyl substituted acylating agents from thereaction of monounsaturated carboxylic acid reactants and compounds ofFormula (I) are well known in the art and disclosed in: U.S. Pat. Nos.3,361,673; 3,401,118; 3,087,436; 3,172,892; 3,272,746, 3,215,707;3,231,587; 3,912,764; 4,110,349; 4,234,435; 6,077,909; and 6,165,235.

In another embodiment, the hydrocarbyl substituted acylating agent canbe made from the reaction of a compound represented by Formula (I) withat least one carboxylic reactant represented by the following formulas:

wherein each of R⁶, R⁸ and R⁹ is independently H or a hydrocarbyl group,R⁷ is a divalent hydrocarbylene group, and n is 0 or 1. Such compoundsand the processes for making them are disclosed in U.S. Pat. Nos.5,739,356; 5,777,142; 5,786,490; 5,856,524; 6,020,500; and 6,114,547.

In yet another embodiment, the hydrocarbyl substituted acylating agentmay be made from the reaction of any compound represented by Formula (I)with any compound represented by Formula (IV) or Formula (V), where thereaction is carried out in the presence of at least one aldehyde orketone. Suitable aldehydes include formaldehyde, acetaldehyde,propionaldehyde, butyraldehyde, isobutyraldehyde, pentanal, hexanal.heptaldehyde, octanal, benzaldehyde, as well as higher aldehydes. Otheraldehydes, such as dialdehydes, especially glyoxal, are useful, althoughmonoaldehydes are generally preferred. In one embodiment, the aldehydeis formaldehyde, which may be supplied in the aqueous solution oftenreferred to as formalin, but which is more often used in the polymericform referred to as paraformaldehyde. Paraformaldehyde is considered areactive equivalent of and/or source of formaldehyde. Other reactiveequivalents include hydrates or cyclic trimers. Suitable ketones includeacetone, butanone, methyl ethyl ketone, as well as other ketones. Insome embodiments, one of the two hydrocarbyl groups of the ketone is amethyl group. Mixtures of two or more aldehydes and/or ketones are alsouseful. Such hydrocarbyl substituted acylating agents and the processesfor making them are disclosed in U.S. Pat. Nos. 5,840,920; 6,147,036;and 6,207,839.

In another embodiment, the hydrocarbyl substituted acylating agent mayinclude methylene bis-phenol alkanoic acid compounds. Such compounds maybe the condensation product of (i) an aromatic compound of the formula:

R_(m)—Ar—Z_(c)   (VI)

and (ii) at least on carboxylic reactant such as the compounds offormula (IV) and (V) described above, wherein, in Formula (VI): each Ris independently a hydrocarbyl group; m is 0 or an integer from 1 up to6 with the proviso that m does not exceed the number of valences of thecorresponding Ar group available for substitution; Ar is an aromaticgroup or moiety containing from 5 to 30 carbon atoms and from 0 to 3optional substituents such as amino, hydroxy- or alkyl-polyoxyalkyl,nitro, aminoalkyl, and carboxy groups, or combinations of two or more ofsaid optional substituents; Z is independently —OH, —O, a lower alkoxygroup, or —(OR¹⁰)_(b)OR₁₁ wherein each R¹⁰ is independently a divalenthydrocarbyl group, b is a number from 1 to 30, and R¹¹ is —H or ahydrocarbyl group; and c is a number ranging from 1 to 3.

In one embodiment, at least one hydrocarbyl group on the aromatic moietyis derived from polybutene. In one embodiment, the source of thehydrocarbyl groups described above are polybutenes obtained bypolymerization of isobutylene in the presence of a Lewis acid catalystsuch as aluminum trichloride or boron trifluoride. Such compounds andthe processes for making them are disclosed in U.S. Pat. Nos. 3,954,808;5,336,278; 5,458,793; 5,620,949; 5,827,805; and 6,001,781.

In another embodiment, the reaction of (i) with (ii), optionally in thepresence of an acidic catalyst such as organic sulfonic acids,heteropolyacids, and mineral acids, can be carried out in the presenceof at least one aldehyde or ketone. The aldehyde or ketone reactantemployed in this embodiment is the same as those described above. Suchcompounds and the processes for making them are disclosed in U.S. Pat.No. 5,620,949. Still other methods of making suitable hydrocarbylsubstituted acylating agents can be found in U.S. Pat. Nos. 5,912,213;5,851,966; and 5,885,944.

The succinimide quaternary ammonium salt detergents are derived byreacting the hydrocarbyl substituted acylating agent described abovewith a compound having an oxygen or nitrogen atom capable of condensingwith the acylating agent. In one embodiment, suitable compounds containat least one tertiary amino group or may be alkylated until they containa tertiary amino group, so long as the hydrocarbyl substituted acylatingagent has at least one tertiary amino group when quaternized.

In one embodiment, this compound may be represented by one of thefollowing formulas:

Wherein, for both Formulas (VII) and (VIII), each X is independently aalkylene group containing 1 to 4 carbon atoms; and each R isindependently a hydrocarbyl group and R′ is a hydrogen or a hydrocarbylgroup.

Suitable compounds include but are not limited to: 1-aminopiperidine,1-(2-aminoethyl)piperidine, 1-(3-aminopropyl)-2-pipecoline,1-methyl-(4-methylamino)piperidine, 1-amino-2,6-dimethylpiperidine,4-(1-pyrrolidinyl)piperidine, 1-(2-aminoethyl)pyrrolidine,2-(2-aminoethyl)-1-methylpyrrolidine, N,N-diethylethylenediamine,N,N-dimethylethylenediamine, N,N-dibutylethylenediamine,N,N,N′-trimethylethylenediamine, N,N-dimethyl-N′-ethylethylenediamine,N,N-diethyl-N′-methylethylenediamine, N,N,N′-triethylethylenediamine,3-dimethylaminopropylamine, 3-diethylaminopropyl-amine,3-dibutylaminopropylamine, N,N,N′-trimethyl-1,3-propanediamine,N,N,2,2-tetramethyl-1,3-propanediamine, 2-amino-5-diethylaminopentane,N,N,N′,N′-tetraethyldiethylenetriamine,3,3′-diamino-N-methyldipropylamine,3,3′-iminobis(N,N-dimethylpropylamine), or combinations thereof. In someembodiments the amine used is 3-dimethylaminopropylamine,3-diethylamino-propylamine, 1-(2-aminoethyl)pyrrolidine,N,N-dimethylethylenediamine, N,N-diethylpropylenediamine or combinationsthereof.

Suitable compounds further include aminoalkyl substituted heterocycliccompounds such as 1-(3-aminopropyl)imidazole and4-(3-aminopropyl)morpholine, 1-(2-aminoethyl)piperidine,3,3-diamino-N-methyldipropylamine,3,3′-aminobis(N,N-dimethylpropylamine) These have been mentioned inprevious list.

Still further nitrogen or oxygen containing compounds capable ofcondensing with the acylating agent which also have a tertiary aminogroup include: alkanolamines, including but not limited totriethanolamine, trimethanolamine, N,N-dimethylaminopropanol,N,N-diethylaminopropanol, N,N-diethylaminobutanol,N,N,N-tris(hydroxyethyl)amine, and N,N,N-tris(hydroxymethyl)amine.

The succinimide quaternary ammonium salt detergents of the presentinvention are formed by combining the reaction product described above(the reaction product of a hydrocarbyl-substituted acylating agent and acompound having an oxygen or nitrogen atom capable of condensing withsaid acylating agent and further having at least one tertiary aminogroup) with a quaternizing agent suitable for converting the tertiaryamino group to a quaternary nitrogen. Suitable quaternizing agents arediscussed in greater detail below. In some embodiments thesepreparations may be carried out neat or in the presence of a solvent, asdescribed above. By way of non-limiting example, preparations ofsuccinimide quaternary ammonium salts are provided below.

In some embodiments the compositions of the invention are substantiallyfree of, or even completely free of, the succinimide quaternary ammoniumsalts described above.

Polyalkene-Substituted Amine Quaternary Ammonium Salts

In one embodiment the quaternary ammonium salt is the reaction productof: (i)(b) a hydrocarbyl-substituted amine having at least one tertiaryamino group; and (ii) a quaternizing agent suitable for converting thetertiary amino group of compound (i) to a quaternary nitrogen, whereinthe hydrocarbyl-substituent is a polyalkene-substituent having a numberaverage molecular weight of from about 100 to about 500, or 100 to 450,or 150 to 400 or 200 to 350.

Suitable polyalkene-substituted amines may be derived from an olefinpolymer and an amine, such as ammonia, monoamines, polyamines ormixtures thereof. They may be prepared by a variety of methods. Suitablepolyalkene-substituted amines or the amines from which they are derivedeither contain a tertiary amino group or may be alkylated until theycontain a tertiary amino group, so long as the polyalkene-substitutedamine has at least one tertiary amino group when it is quaternized.

One method of preparation of a polyalkene-substituted amine involvesreacting a halogenated olefin polymer with an amine, as disclosed inU.S. Pat. Nos. 3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,755,433;and 3,822,289. Another method of preparation of a polyalkene-substitutedamine involves reaction of a hydro-formylated olefin with a polyamineand hydrogenating the reaction product, as disclosed in U.S. Pat. Nos.5,567,845 and 5,496,383. Another method for preparing apolyalkene-substituted amine involves converting a polyalkene, by meansof a conventional epoxidation reagent, with or without a catalyst, intothe corresponding epoxide and converting the epoxide into the polyalkenesubstituted amine by reaction with ammonia or an amine under theconditions of reductive amination, as disclosed in U.S. Pat. No.5,350,429. Another method for preparing a polyalkene-substituted amineinvolves hydrogenation of a β-aminonitrile, made by reacting an aminewith a nitrile, as disclosed in U.S. Pat. No. 5,492,641. Yet anothermethod for preparing a polyalkene-substituted amine involveshydroformylating polybutene or polyisobutylene, with a catalyst, such asrhodium or cobalt, in the presence of CO, H₂ and NH₃ at elevatedpressures and temperatures, as disclosed in U.S. Pat. Nos.: 4,832,702;5,496,383 and 5,567,845. The above methods for the preparation ofpolyalkene substituted amine are for illustrative purposes only and arenot meant to be an exhaustive list. The polyalkene-substituted amines ofthe present invention are not limited in scope to the methods of theirpreparation disclosed hereinabove.

The polyalkene-substituted amine may be derived from olefin polymers.Suitable olefin polymers for preparing the polyalkene-substituted aminesof the invention are the same as those described above.

The polyalkene-substituted amine may be derived from ammonia,monoamines, polyamines, or mixtures thereof, including mixtures ofdifferent monoamines, mixtures of different polyamines, and mixtures ofmonoamines and polyamines (which include diamines). Suitable aminesinclude aliphatic, aromatic, heterocyclic and carbocyclic amines.

In one embodiment, the amines may be characterized by the formula:

R¹²R¹³NH   (IX)

wherein R¹² and R¹³ are each independently hydrogen, hydrocarbon,amino-substituted hydrocarbon, hydroxy-substituted hydrocarbon,alkoxy-substituted hydrocarbon, or acylimidoyl groups provided that nomore than one of R¹² and R¹³ is hydrogen. The amine may be characterizedby the presence of at least of at least one primary (H₂N—) or secondaryamino (H—N<) group. These amines, or the polyalkene-substituted aminesthey are used to prepare may be alkylated as needed to ensure theycontain at least one tertiary amino group. Examples of suitablemonoamines include ethylamine, dimethylamine, diethylamine,n-butylamine, dibutylamine, allylamine, isobutylamine, cocoamine,stearylamine, laurylamine, methyllaurylamine, oleylamine,N-methyl-octylamine, dodecyl-amine, diethanolamine, morpholine, andoctadecylamine.

The polyamines from which the detergent is derived include principallyalkylene amines conforming, for the most part, to the formula:

wherein n is an integer typically less than 10, each R¹⁴ isindependently hydrogen or a hydrocarbyl group typically having up to 30carbon atoms, and the alkylene group is typically an alkylene grouphaving less than 8 carbon atoms. The alkylene amines includeprincipally, ethylene amines, hexylene amines, heptylene amines,octylene amines, other polymethylene amines. They are exemplifiedspecifically by: ethylenediamine, diethylenetriamine, triethylenetetramine, propylene diamine, decamethylene diamine, octamethylenediamine, di(heptamethylene) triamine, tripropylene tetramine,tetraethylene pentamine, trimethylene diamine, pentaethylene hexamine,di(-trimethylene)triamine, aminopropylmorpholine anddimethylaminopropylamine. Higher homologues such as are obtained bycondensing two or more of the above-illustrated alkylene amines likewiseare useful. Tetraethylene pentamine is particularly useful.

The ethylene amines, also referred to as polyethylene polyamines, areespecially useful. They are described in some detail under the heading“Ethylene Amines” in Encyclopedia of Chemical Technology, Kirk andOthmer, Vol. 5, pp. 898-905, Interscience Publishers, New York (1950).

Any of the above polyalkene-substituted amines, or the amines from whichthey are derived, which are secondary or primary amines, may bealkylated to tertiary amines using alkylating agents before or whilethey are reacted with the quaternizing agents to form the quaternaryammonium salt additives of the present invention. Suitable alkylatingagents include the quaternizing agents discussed below.

The polyalkene-substituted amine quaternary ammonium salts of thepresent invention are formed by combining the reaction product describedabove (the polyalkene-substituted amine, having at least one tertiaryamino group) with a quaternizing agent suitable for converting thetertiary amino group to a quaternary nitrogen. Suitable quaternizingagents are discussed in greater detail below. By way of non-limitingexample, a preparation of a polyalkene-substituted amine quaternaryammonium salt is provided below.

In some embodiments the compositions of the invention are substantiallyfree of, or even completely free of, the polyalkene-substituted aminequaternary ammonium salts described above.

Polyester Quaternary Ammonium Salts

In some embodiments the hydrocarbyl-substituent of the quaternaryammonium salt is a polyester having a number average molecular weight offrom about 100 to about 500, or 100 to 450, or 150 to 400 or 200 to 350.The polyester quaternary salt may include quaternized polyester amine,amide, and ester salts. Such additives may also be described asquaternary polyester salts. The additives of the invention may bedescribed as the reaction product of: a polyester containing a tertiaryamino group; and a quaternizing agent suitable for converting thetertiary amino group to a quaternary nitrogen. The quaternary agents maybe any of the agents described hereinabove.

The polyester containing a tertiary amino group used in the preparationof the additives of the invention may also be described as anon-quaternized polyester containing a tertiary amino group.

In some embodiments the polyester is the reaction product of a fattycarboxylic acid containing at least one hydroxyl group and a compoundhaving an oxygen or nitrogen atom capable of condensing with said acidfurther having a tertiary amino group. Suitable fatty carboxylic acidsto use in the preparation of the polyesters described above may berepresented by the formula:

where R¹ is a hydrogen or a hydrocarbyl group containing from 1 to 20carbon atoms and R² is a hydrocarbylene group containing from 1 to 20carbon atoms. In some embodiments R¹ contains from 1 to 12, 2 to 10, 4to 8 or even 6 carbon atoms, and R² contains from 2 to 16, 6 to 14, 8 to12, or even 10 carbon atoms.

In some embodiments the fatty carboxylic acid used in the preparation ofthe polyester is 12-hydroxystearic acid, ricinoleic acid, 12-hydroxydodecanoic acid, 5-hydroxy dodecanoic acid, 5-hydroxy decanoic acid,4-hydroxy decanoic acid, 10-hydroxy undecanoic acid, or combinationsthereof.

In some embodiments the compound having an oxygen or nitrogen atomcapable of condensing with said acid and further having a tertiary aminogroup is represented by the formula:

where R³ is a hydrocarbyl group containing from 1 to 10 carbon atoms; R⁴is a hydrocarbyl group containing from 1 to 10 carbon atoms; R⁵ is ahydrocarbylene group containing from 1 to 20 carbon atoms; and X¹ is Oor NR⁶ where R⁶ is a hydrogen or a hydrocarbyl group containing from 1to 10 carbon atoms. In some embodiments R³ contains from 1 to 6, 1 to 2,or even 1 carbon atom, R⁴ contains from 1 to 6, 1 to 2, or even 1 carbonatom, R⁵ contains from 2 to 12, 2 to 8 or even 3 carbon atoms, and R⁶contains from 1 to 8, or 1 to 4 carbon atoms. In some of theseembodiments, formula (XII) becomes:

where the various definitions provided above still apply.

Examples of nitrogen or oxygen containing compounds capable ofcondensing with the acylating agents, which also have a tertiary aminogroup, or compounds that can be alkylated into such compounds, includeany of the materials described in the sections above.

The nitrogen or oxygen containing compounds may further includeaminoalkyl substituted heterocyclic compounds such as1-(3-aminopropyl)imidazole and 4-(3-aminopropyl)morpholine.

In one embodiment the nitrogen or oxygen containing compound istriisopropanolamine, 1-[2-hydroxyethyl]piperidine,2-[2-(dimethylamino)ethoxy]-ethanol, N-ethyldiethanolamine,N-methyldiethanolamine, N-butyldiethanolamine, N,N-diethylamino ethanol,N,N-dimethylaminoethanol, 2-dimethylamino-2-methyl-1-propanol, orcombinations thereof.

In some embodiments the compound having an oxygen or nitrogen atomcapable of condensing with said acid and further having a tertiary aminogroup comprises N,N-diethylethylenediamine, N,N-dimethylethylenediamine,N,N-dibutylethylenediamine, N,N-dimethyl-1,3-diaminopropane,N,N-diethyl-1,3-diaminopropane, N,N-dimethylaminoethanol,N,N-diethylaminoethanol, N,N-diethylpropylenediamine or combinationsthereof.

The quaternized polyester salt can be a quaternized polyester amidesalt. In such embodiments the polyester containing a tertiary aminogroup used to prepare the quaternized polyester salt is a polyesteramide containing a tertiary amino group. In some of these embodimentsthe amine or amino alcohol is reacted with a monomer and then theresulting material is polymerized with additional monomer, giving thepolyester amide which may then be quaternized.

In some embodiments the quaternized polyester salt includes a cationrepresented by the following formula:

where R¹ is a hydrogen or a hydrocarbyl group containing from 1 to 3carbon atoms and R² is a hydrocarbylene group containing from 1 to 4carbon atoms; R³ is a hydrocarbyl group containing from 1 to 3 carbonatoms; R⁴ is a hydrocarbyl group containing from 1 to 3 carbon atoms; R⁵is a hydrocarbylene group containing from 1 or 2 to 6 carbon atoms; R⁶is a hydrogen or a hydrocarbyl group containing from 1 to 3 carbonatoms; n is a number from 1 to about 7 or from 1 to about 5; R⁷ ishydrogen, a hydrocarbonyl group containing from 1 to 3 carbon atoms, ora hydrocarbyl group containing from 1 to 3 carbon atoms; and X² is agroup derived from the quaternizing agent. In some embodiments R⁶ ishydrogen.

As above, in some embodiments R¹ contains from 1 to 2, 2 to 3, or 1carbon atoms, and R² contains from 1 to 2, or 2 to 3, or 1 carbon atoms,R³ contains from 1 to 2, 2 to 3, or even 1 carbon atom, R⁴ contains from1 to 2, 2 to 3, or even 1 carbon atom, R⁵ contains from 1 to 2, 2 to 3or even 1 carbon atoms, and R⁶ contains from 1 to 2, or 2 to 3, or even1 carbon atoms. In any of these embodiments n may be from 2 to 7, or 3to 6, and R⁷ may contain from 1 to 2, or 2 to 3, or 1 carbon atoms. R⁷may be an acyl group.

In these embodiments the quaternized polyester salt is essentiallycapped with a C1-22, or a C8-20, fatty acid. Examples of suitable acidsinclude oleic acid, palmitic acid, stearic acid, erucic acid, lauricacid, 2-ethylhexanoic acid, 9,11-linoleic acid, 9,12-linoleic acid,9,12,15-linolenic acid, abietic acid, or combinations thereof.

The number average molecular weight (Mn) of the fully quaternizedpolyester salts of the invention may be from about 100 to about 750, orfrom about 200 to about 700, or from about 100 to about 500.

The polyester useful in the present invention can be obtained by heatingone or more hydroxycarboxylic acids or a mixture of thehydroxycarboxylic acid and a carboxylic acid, optionally in the presenceof an esterification catalyst. The hydroxycarboxylic acids can have theformula HO—X—COOH wherein X is a divalent saturated or unsaturatedaliphatic radical containing at least 8 carbon atoms and in which thereare at least 4 carbon atoms between the hydroxy and carboxylic acidgroups, or from a mixture of such a hydroxycarboxylic acid and acarboxylic acid which is free from hydroxy groups. This reaction can becarried out at a temperature in the region of 160 C to 200 C, until thedesired molecular weight has been obtained. The course of theesterification can be followed by measuring the acid value of theproduct, with the desired polyester, in some embodiments, having an acidvalue in the range of 1 to 200 mg KOH/g or in the range of 10 to 150 mgKOH/g. The indicated acid value range of 1 to 200 mg KOH/g is equivalentto a number average molecular weight range of 56100 to 280. The waterformed in the esterification reaction can be removed from the reactionmedium, and this can be conveniently done by passing a stream ofnitrogen over the reaction mixture or, by carrying out the reaction inthe presence of a solvent, such as toluene or xylene, and distilling offthe water as it is formed.

The resulting polyester can then be isolated in conventional manner;however, when the reaction is carried out in the presence of an organicsolvent whose presence would not be harmful in the subsequentapplication, the resulting solution of the polyester can be used.

In the said hydroxycarboxylic acids the radical represented by X maycontain from 12 to 20 carbon atoms, optionally where there are between 8and 14 carbon atoms between the carboxylic acid and hydroxy groups. Insome embodiments the hydroxy group is a secondary hydroxy group.

Specific examples of such hydroxycarboxylic acids include ricinoleicacid, a mixture of 9- and 10-hydroxystearic acids (obtained bysulphation of oleic acid and then hydrolysis), and 12-hydroxystearicacid, and the commercially available hydrogenated castor oil fatty acidwhich contains in addition to 12-hydroxystearic acid minor amounts ofstearic acid and palmitic acid.

The carboxylic acids which can be used in conjunction with thehydroxycarboxylic acids to obtain these polyesters are preferablycarboxylic acids of saturated or unsaturated aliphatic compounds,particularly alkyl and alkenyl carboxylic acids containing a chain offrom 8 to 20 carbon atoms. As examples of such acids there may bementioned lauric acid, palmitic acid, stearic acid and oleic acid.

In one embodiment the polyester is derived from commercial12-hydroxy-stearic acid having a number average molecular weight ofabout 1600. Polyesters such as this are described in greater detail inU.K. Patent Specification Nos. 1373660 and 1342746.

In some embodiments the components used to prepare the additivesdescribed above are substantially free of, essentially free of, or evencompletely free of, non-polyester-containing hydrocarbyl substitutedacylating agents and/or non-polyester-containing hydrocarbyl substituteddiacylating agents, such as for example polyisobutylene. In someembodiments these excluded agents are the reaction product of a longchain hydrocarbon, generally a polyolefin reacted with a monounsaturatedcarboxylic acid reactant, such as, (i) α,β-monounsaturated C₄ to C₁₀dicarboxylic acid, such as, fumaric acid, itaconic acid, maleic acid.;(ii) derivatives of (i) such as anhydrides or C₁ to C₅ alcohol derivedmono- or di-esters of (i); (iii) α,β-monounsaturated C₃ to C₁₀monocarboxylic acid such as acrylic acid and methacrylic acid.; or (iv)derivatives of (iii), such as, C₁ to C₅ alcohol derived esters of (iii)with any compound containing an olefinic bond represented by the generalformula (R⁹)(R¹⁰)C═C(R¹¹)(CH(R⁷)(R⁸)) wherein each of R⁹ and R¹⁰ isindependently hydrogen or a hydrocarbon based group; each of R¹¹, R⁷ andR⁸ is independently hydrogen or a hydrocarbon based group and preferablyat least one is a hydrocarbyl group containing at least 20 carbon atoms.In one embodiment, the excluded hydrocarbyl-substituted acylating agentis a dicarboxylic acylating agent. In some of these embodiments, theexcluded hydrocarbyl-substituted acylating agent is polyisobutylenesuccinic anhydride.

By substantially free of, it is meant that the components of the presentinvention are primarily composed of materials other than hydrocarbylsubstituted acylating agents described above such that these agents arenot significantly involved in the reaction and the compositions of theinvention do not contain significant amounts of additives derived fromsuch agents. In some embodiments the components of the invention, or thecompositions of the invention, may contain less than 10 percent byweight of these agents, or of the additives derived from these agents.In other embodiments the maximum allowable amount may be 5, 3, 2, 1 oreven 0.5 or 0.1 percent by weight. One of the purposes of theseembodiments is to allow the exclusion of agents such as polyisobutylenesuccinic anhydrides from the reactions of the invention and so, to alsoallow the exclusion of quaternized salt detergent additive derived fromagents such as polyisobutylene succinic anhydrides. The focus of thisembodiment is on polyester, or hyperdispersant, quaternary saltdetergent additives.

In some embodiments the compositions of the invention are substantiallyfree of, or even completely free of, the polyester quaternary saltsdescribed above.

Mannich Quaternary Ammonium Salts

In one embodiment the quaternary ammonium salt is the reaction productof: (i)(c) a Mannich reaction product; and (ii) a quaternizing agentsuitable for converting the tertiary amino group of compound (i) to aquaternary nitrogen. Suitable Mannich reaction products have at leastone tertiary amino group and are prepared from the reaction of ahydrocarbyl-substituted phenol, an aldehyde, and an amine.

The hydrocarbyl substituent of the hydrocarbyl-substituted phenol canhave 1 to 36 carbon atoms, in another instance 2 to 34 carbon atoms, andin a further instance 5 or 8 to 30 carbon atoms. This hydrocarbylsubstituent can be derived from an olefin or a polyolefin. Usefulolefins include alpha-olefins, such as 1-decene, which are commerciallyavailable. Suitable polyolefins include those described in the sectionsabove. The hydrocarbyl-substituted phenol can be prepared by alkylatingphenol with one of these suitable olefins or polyolefins, such as apolyisobutylene or polypropylene, using well-known alkylation methods.

The aldehyde used to form the Mannich detergent can have 1 to 10 carbonatoms, and is generally formaldehyde or a reactive equivalent thereof,such as formalin or paraformaldehyde.

The amine used to form the Mannich detergent can be a monoamine or apolyamine. Amines suitable for preparing the Mannich reaction product ofthe invention are the same as those are described in the sections above.

In one embodiment, the Mannich detergent is prepared by reacting ahydrocarbyl-substituted phenol, an aldehyde, and an amine, as describedin U.S. Pat. No. 5,697,988. In one embodiment, the Mannich reactionproduct is prepared from: an alkylphenol derived from a polyisobutylene;formaldehyde; and a primary monoamine, secondary monoamine, oralkylenediamine. In some of such embodiments the amine isethylenediamine or dimethylamine. Other methods of preparing suitableMannich reaction products can be found in U.S. Pat. Nos. 5,876,468 and5,876,468.

As discussed above, it may be necessary, with some of the amines, tofurther react the Mannich reaction product with an epoxide or carbonate,or other alkylating agent, in order to obtain the tertiary amino group.

The Mannich quaternary ammonium salts of the present invention areformed by combining the reaction product described above (the Mannichreaction product with at least one tertiary amino group) with aquaternizing agent suitable for converting the tertiary amino group to aquaternary nitrogen. Suitable quaternizing agents are discussed below.

In some embodiments the compositions of the invention are substantiallyfree of, or even completely free of, the Mannich quaternary ammoniumsalts described above.

Amide and/or Ester Quaternary Ammonium Salts

In some embodiments the quaternary ammonium salts used in the inventionare quaternary amide and/or ester detergents which may be described asthe reaction product of: (i) a non-quaternized amide and/or esterdetergent having a tertiary amine functionality; and (ii) a quaternizingagent. In some embodiments the non-quaternized detergent is thecondensation product of (a) a hydrocarbyl-substituted acylating agentand (b) a compound having an oxygen or nitrogen atom capable ofcondensing with said acylating agent and further having at least onetertiary amino group.

The non-quaternized amide and/or ester detergents suitable for use inthe present invention include the condensation product of (i) ahydrocarbyl-substituted acylating agent and (ii) a compound having anoxygen or nitrogen atom capable of condensing with said acylating agentand further having at least one tertiary amino group, where theresulting detergent has at least one tertiary amino group and alsocontains an amide group and/or an ester group. Typically, the compoundhaving an oxygen or nitrogen atom capable of condensing with saidacylating agent determines whether the resulting detergent contains anamide group or an ester group. In some embodiments, the non-quaternizeddetergent, and so the resulting quaternized detergent is free of anyimide groups. In some embodiments, the non-quaternized detergent, and sothe resulting quaternized detergent is free of any ester groups. Inthese embodiments the detergent contains at least one, or just one,amide group.

The hydrocarbyl substituted acylating agent can be any of the materialsdescribed in section above provided that the material contains an amidegroup and/or an ester group.

The non-quaternized amide and/or ester detergent used to prepare theadditives of the present invention are themselves formed when theacylating agents described above are reacted with a compound having anoxygen or nitrogen atom capable of condensing with the acylating agentwhich further has at least one tertiary amino group. Any of thesecompounds described above may be used here as well.

In one embodiment, the non-quaternized amide and/or ester group cancomprise a hydrocarbyl substituted dicarboxylic acid, for example, asuccinic acid, free of any imide groups, wherein one of the carboxylicacid moieties reacts with the compound having an oxygen or nitrogen atomcapable of condensing with the acylating agent to form an amide and theother carboxylic acid moiety remains an acid group. In anotherembodiment, the non-quaternized amide and/or ester group can comprise ahydrocarbyl substituted dicarboxylic acid, for example, a succinic acid,free of any anhydride groups, wherein one of the carboxylic acidmoieties reacts with the compound having an oxygen or nitrogen atomcapable of condensing with the acylating agent to form an ester and theother carboxylic acid moiety remains an acid group.

In further embodiments, the non-quaternized amide and/or ester group canbe represented by the following formula:

wherein: R²¹ is a hydrocarbyl group containing from 1 to 3 carbon atoms;R²² is a hydrocarbyl group containing from 1 to 3 carbon atoms; R²³ is ahydrocarbylene group containing from 1 to 3 carbon atoms; R²⁴ is ahydrocarbyl group containing from 7 to 36 carbon atoms; and Y is NH orO.

The quaternary amide and/or ester detergents are prepared by reacting(a) the non-quaternized amide and/or ester detergent having a tertiaryamine functionality with (b) the quaternizing agent; thereby obtainingthe quaternized detergent. The processes of the present invention mayalso be described as a process for preparing a quaternized amide and/orester detergent comprising the steps of: (1) mixing (a) anon-quaternized amide and/or ester detergent having an aminefunctionality, (b) a quaternizing agent and optionally with (c) a proticsolvent, which in some embodiments is free of methanol; (2) heating themixture to a temperature between 50° C. to 130° C.; and (3) holding forthe reaction to complete; thereby obtaining the quaternized amide and/orester detergent. In one embodiment the reaction is carried out at atemperature of less than 80° C., or less than 70° C. In otherembodiments the reaction mixture is heated to a temperature of about 50°C. to 120° C., 80° C., or 70° C. In still other embodiments where thehydrocarbyl acylating agent is derived from a monocarboxylic acid, thereaction temperature may be 70° C. to 130° C. In other embodiments wherethe hydrocarbyl acylating agent is derived from a dicarboxylic acid, thereaction temperature may be 50° C. to 80° C. or 50° C. to 70° C. In someembodiments the processes of the present invention are free of theaddition of any acid reactant, such as acetic acid. The salt product isobtained in these embodiments despite the absence of the separate acidreactant.

As described above, in some embodiments the non-quaternized amide and/orester detergent is the condensation product of hydrocarbyl-substitutedacylating agent and a compound having an oxygen or nitrogen atom capableof condensing with said acylating agent and further having at least onetertiary amino group. Suitable quaternizing agents and compounds havingan oxygen or nitrogen atom are also described above.

The additives of the present invention may be derived in the presence ofa protic solvent. In some embodiments the process used to prepare theseadditives is substantially free of to free of methanol. Substantiallyfree of methanol can mean less than 0.5, 0.1 or 0.05 percent by weightmethanol in the reaction mixture, and may also mean completely free ofmethanol.

Suitable protic solvents include solvents that have dielectric constantsof greater than 9. In one embodiment the protic solvent includescompounds that contain 1 or more hydroxyl functional groups, and mayinclude water.

In one embodiment, the solvents are glycols and glycol ethers. Glycolscontaining from 2 to 12 carbon atoms, or from 4 to 10, or 6 to 8 carbonatoms, and oligomers thereof (e.g., dimers, trimers and tetramers) aregenerally suitable for use. Illustrative glycols include ethyleneglycol, propylene glycol, diethylene glycol, dipropylene glycol,1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, triethyleneglycol, polyethylene glycol and the like and oligomers and polymericderivative and mixtures thereof. Illustrative glycol ethers include theC₁-C₆ alkyl ethers of propylene glycol, ethylene glycol and oligomersthereof such as di-, tri- and tetra glycol ethers of methyl, ethyl,propyl, butyl or hexyl. Suitable glycol ethers include ethers ofdipropylene glycol, tripropylene glycol diethylene glycol, triethyleneglycol; ethyl diglycol ether, butyl diglycol ether, methoxytriglycol,ethoxytriglycol, butoxytriglycol, methoxytetraglycol, butoxytetraglycol.

Suitable solvents for use in the invention also include certainalcohols. In one embodiment, these alcohols contain at least 2 carbonatoms, and in other embodiments at least 4, at least 6 or at least 8carbon atoms. In another embodiment, the solvent of the presentinvention contains 2 to 20 carbon atoms, 4 to 16 carbon atoms, 6 to 12carbon atoms, 8 to 10 carbon atoms, or just 8 carbon atoms. Thesealcohols normally have a 2-(C₁₋₄ alkyl) substituent, namely, methyl,ethyl, or any isomer of propyl or butyl. Examples of suitable alcoholsinclude 2-methylheptanol, 2-methyldecanol, 2-ethylpentanol,2-ethylhexanol, 2-ethylnonanol, 2-propylheptanol, 2-butylheptanol,2-butyloctanol, isooctanol, dodecanol, cyclohexanol, methanol, ethanol,propan-1-ol, 2-methylpropan-2-ol, 2-methylpropan-1-ol, butan-1-ol,butan-2-ol, pentanol and its isomers, and mixtures thereof. In oneembodiment the solvent of the present invention is 2-ethylhexanol,2-ethyl nonanol, 2-propylheptanol, or combinations thereof. In oneembodiment the solvent of the present invention includes 2-ethylhexanol.

The solvent can be any of the commercially available alcohols ormixtures of such alcohols and also includes such alcohols and mixturesof alcohols mixed with water. In some embodiments the amount of waterpresent may be above 1 percent by weight of the solvent mixture. Inother embodiments the solvent mixture may contain traces of water, withthe water content being less than 1 or 0.5 percent by weight.

The alcohols can be aliphatic, cycloaliphatic, aromatic, orheterocyclic, including aliphatic-substituted cycloaliphatic alcohols,aliphatic-substituted aromatic alcohols, aliphatic-substitutedheterocyclic alcohols, cycloaliphatic-substituted aliphatic alcohols,cycloaliphatic-substituted aromatic alcohols, cycloaliphatic-substitutedheterocyclic alcohols, heterocyclic-substituted aliphatic alcohols,heterocyclic-substituted cycloaliphatic alcohols, andheterocyclic-substituted aromatic alcohols.

While not wishing to be bound by theory, it is believed that a polarprotic solvent is required in order to facilitate the dissociation ofthe acid into ions and protons. The dissociation is required toprotonate the ion formed when the detergent having an aminefunctionality initially reacts with the quaternizing agent. In the casewhere the quaternizing agent is an alkyl epoxide the resulting ion wouldbe an unstable alkoxide ion. The dissociation also provides a counterion from the acid group of the additive that acts to stabilize thequaternary ammonium ion formed in the reaction, resulting in a morestable product.

The solvent may be present such that the weight ratio of the amount ofdetergent having an amine functionality to the amount of polar solventis in one set of embodiments from 20:1 to 1:20; or from 10:1 to 1:10. Inadditional embodiments, the detergent to solvent weight ratio can befrom 1:10 to 1:15; from 15:1 to 10:1; or from 5:1 to 1:1.

In some embodiments the compositions of the invention are substantiallyfree of, or even completely free of, the quaternary amide and/or esterdetergents described above.

The Quaternizing Agent

Suitable quaternizing agents for preparing any of the quaternaryammonium salt detergents described above include dialkyl sulfates,benzyl halides, hydrocarbyl substituted carbonates, hydrocarbyl epoxidesused in combination with an acid, esters of polycarboxylic acids, ormixtures thereof.

In one embodiment the quaternizing agent includes: halides such aschloride, iodide or bromide; hydroxides; sulphonates; alkyl sulphatessuch as dimethyl sulphate; sultones; phosphates; C₁₋₁₂ alkylphosphates;di-C₁₋₁₂ alkylphosphates; borates; C₁₋₁₂ alkylborates; nitrites;nitrates; carbonates; bicarbonates; alkanoates; O,O-di-C₁₋₁₂alkyldithiophosphates; or mixtures thereof.

In one embodiment the quaternizing agent may be: a dialkyl sulphate suchas dimethyl sulphate; N-oxides; sultones such as propane or butanesultone; alkyl, acyl or aralkyl halides such as methyl and ethylchloride, bromide or iodide or benzyl chloride; hydrocarbyl (or alkyl)substituted carbonates; or combinations thereof. If the aralkyl halideis benzyl chloride, the aromatic ring is optionally further substitutedwith alkyl or alkenyl groups.

The hydrocarbyl (or alkyl) groups of the hydrocarbyl substitutedcarbonates may contain 1 to 50, 1 to 20, 1 to 10 or 1 to 5, or 1 to 3carbon atoms per group. In one embodiment the hydrocarbyl substitutedcarbonates contain two hydrocarbyl groups that may be the same ordifferent. Examples of suitable hydrocarbyl substituted carbonatesinclude dimethyl or diethyl carbonate.

In another embodiment the quaternizing agent can be a hydrocarbylepoxides, as represented by the following formula:

wherein R¹⁵, R¹⁶, R¹⁷ and R¹⁸ can be independently H or a C₁₋₅₀hydrocarbyl group. Examples of suitable hydrocarbyl epoxides include:styrene oxide, ethylene oxide, propylene oxide, butylene oxide, stilbeneoxide, C₂₋₅₀ epoxides, or combinations thereof.

In another embodiment the quaternizing agent can be an ester of acarboxylic acid capable of reacting with a tertiary amine to form aquaternary ammonium salt, or an ester of a polycarboxylic acid. In ageneral sense such materials may be described as compounds having thestructure:

R¹⁹—C(═O)—O—R²   (XV)

where R¹⁹ is an optionally substituted alkyl, alkenyl, aryl or alkylarylgroup and R²⁰ is a hydrocarbyl group containing from 1 to 22 carbonatoms.

Suitable compounds include esters of carboxylic acids having a pKa of3.5 or less. In some embodiments the compound is an ester of acarboxylic acid selected from a substituted aromatic carboxylic acid, ana-hydroxycarboxylic acid and a polycarboxylic acid. In some embodimentsthe compound is an ester of a substituted aromatic carboxylic acid andthus R¹⁹ is a substituted aryl group. R may be a substituted aryl grouphaving 6 to 10 carbon atoms, a phenyl group, or a naphthyl group. R maybe suitably substituted with one or more groups selected fromcarboalkoxy, nitro, cyano, hydroxy, SR′ or NR′R″ where each of R′ and R″may independently be hydrogen, or an optionally substituted alkyl,alkenyl, aryl or carboalkoxy groups. In some embodiments R′ and R″ areeach independently hydrogen or an optionally substituted alkyl groupcontaining from 1 to 22, 1 to 16, 1 to 10, or even 1 to 4 carbon atoms.

In some embodiments R¹⁹ in the formula above is an aryl groupsubstituted with one or more groups selected from hydroxyl, carboalkoxy,nitro, cyano and NH². R¹⁹ may be a poly-substituted aryl group, forexample trihydroxyphenyl, but may also be a mono-substituted aryl group,for example an ortho substituted aryl group. R¹⁹ may be substituted witha group selected from OH, NH₂, NO₂, or COOMe. Suitably R¹⁹ is a hydroxysubstituted aryl group. In some embodiments R¹⁹ is a 2-hydroxyphenylgroup. R²⁰ may be an alkyl or alkylaryl group, for example an alkyl oralkylaryl group containing from 1 to 16 carbon atoms, or from 1 to 10,or 1 to 8 carbon atoms. R²⁰ may be methyl, ethyl, propyl, butyl, pentyl,benzyl or an isomer thereof. In some embodiments R²⁰ is benzyl ormethyl. In some embodiments the quaternizing agent is methyl salicylate.

In some embodiments the quaternizing agent is an ester of analpha-hydroxycarboxylic acid. Compounds of this type suitable for useherein are described in EP 1254889. Examples of suitable compounds whichcontain the residue of an alpha-hydroxycarboxylic acid include (i)methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, benzyl-, phenyl-, andallyl esters of 2-hydroxyisobutyric acid; (ii) methyl-, ethyl-, propyl-,butyl-, pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of2-hydroxy-2-methylbutyric acid; (iii) methyl-, ethyl-, propyl-, butyl-,pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of2-hydroxy-2-ethylbutyric acid; (iv) methyl-, ethyl-, propyl-, butyl-,pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of lactic acid; and(v) methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, allyl-, benzyl-,and phenyl esters of glycolic acid. In some embodiments the quaternizingagent comprises methyl 2-hydroxyisobutyrate.

In some embodiments the quaternizing agent comprises an ester of apolycarboxylic acid. In this definition we mean to include dicarboxylicacids and carboxylic acids having more than 2 acidic moieties. In someembodiments the esters are alkyl esters with alkyl groups that containfrom 1 to 4 carbon atoms. Suitable example include diesters of oxalicacid, diesters of phthalic acid, diesters of maleic acid, diesters ofmalonic acid or diesters or triesters of citric acid.

In some embodiments the quaternizing agent is an ester of a carboxylicacid having a pKa of less than 3.5. In such embodiments in which thecompound includes more than one acid group, we mean to refer to thefirst dissociation constant. The quaternizing agent may be selected froman ester of a carboxylic acid selected from one or more of oxalic acid,phthalic acid, salicylic acid, maleic acid, malonic acid, citric acid,nitrobenzoic acid, aminobenzoic acid and 2,4,6-trihydroxybenzoic acid.In some embodiments the quaternizing agent includes dimethyl oxalate,methyl 2-nitrobenzoate and methyl salicylate.

Any of the quaternizing agents described above, including thehydrocarbyl epoxides, may be used in combination with an acid. Suitableacids include carboxylic acids, such as acetic acid, propionic acid,2-ethylhexanoic acid, and the like. In some embodiments, for examplewhen the hydrocarbyl acylating agent is a dicarboxylic acylating agent,no separate acid component is needed. In such embodiments, the detergentmay be prepared by combining reactants which are essentially free tofree of an acid component, such as acetic acid, and rely on the acidgroup of the hydrocarbyl acylating agent instead.

In some embodiments the quaternary ammonium salt includes the reactionproduct of: (i) a compound comprising at least one tertiary amino group;and (ii) a quaternizing agent suitable for converting the tertiary aminogroup of compound (i) to a quaternary nitrogen, where component (i), thecompound comprising at least one tertiary amino group, comprises: (a)the condensation product of a hydrocarbyl-substituted acylating agentand a compound having an oxygen or nitrogen atom capable of condensingthe acylating agent wherein the condensation product has at least onetertiary amino group.

In some embodiments the hydrocarbyl-substituted acylating agent may bepolyisobutylene succinic anhydride and the compound having an oxygen ornitrogen atom capable of condensing with said acylating agent may bedimethylaminopropylamine, dimethyl ethanolamine, diethyl ethanolamine,N-methyl-1,3-diaminopropane, N,N-dimethyl-aminopropylamine,N,N-diethyl-aminopropylamine, N,N-dimethyl-aminoethylamine,diethylenetriamine, dipropylenetriamine, dibutylenetriamine,triethylenetetraamine, tetraethylenepentaamine, pentaethylenehexaamine,hexamethylenetetramine, and bis(hexamethylene)triamine.

In some embodiments the quaternary ammonium salt comprises an cationrepresented by the following formula:

wherein: R²¹ is a hydrocarbyl group containing from 1 to 3 carbon atoms;R²² is a hydrocarbyl group containing from 1 to 3 carbon atoms; R²³ is ahydrocarbylene group containing from 1 to 3 carbon atoms; R²⁴ is ahydrocarbyl group containing from 7 to 36 carbon atoms; and X is a groupderived from the quaternizing agent.

In some embodiments the quaternary ammonium salt includes the reactionproduct of: (i) a compound comprising at least one tertiary amino group;and (ii) a quaternizing agent suitable for converting the tertiary aminogroup of compound (i) to a quaternary nitrogen, where component (i), thecompound comprising at least one tertiary amino group, comprises: (b) apolyalkene-substituted amine having at least one tertiary amino group.

In some embodiments the polyalkene substituent of thepolyalkene-substituted amine is derived from polyisobutylene and thepolyalkene-substituted amine has a number average molecular weight ofabout 100 to about 500.

In some embodiments the quaternary ammonium salt includes the reactionproduct of: (i) a compound comprising at least one tertiary amino group;and (ii) a quaternizing agent suitable for converting the tertiary aminogroup of compound (i) to a quaternary nitrogen, where component (i), thecompound comprising at least one tertiary amino group, comprises: (c) aMannich reaction product having at least one tertiary amino group,wherein the Mannich reaction product is derived from ahydrocarbyl-substituted phenol, an aldehyde, and an amine.

In some embodiments component (i), the compound comprising at least onetertiary amino group, comprises a Mannich reaction product having atertiary amino group, said Mannich reaction product being prepared fromthe reaction of a hydrocarbyl-substituted phenol, an aldehyde, and anamine; and wherein the hydrocarbyl substituent of thehydrocarbyl-substituted phenol of component (a) is derived from apolyolefin having a number average molecular weight of 100 to about 400;wherein the aldehyde of component (a) is a formaldehyde or a reactiveequivalent thereof; and wherein the amine of component (a) is selectedfrom the group consisting of dimethylamine, ethylenediamine,dimethylaminopropylamine, diethylenetriamine, dibutylamine, and mixturesthereof.

In any of these embodiments described above, any of one or combinationof quaternizing agents described above may be used.

INDUSTRIAL APPLICATION

In one embodiment the invention is useful as a liquid fuel for aninternal combustion engine. The internal combustion engine includesspark ignition and compression ignition engines; 2-stroke or 4-strokecycles; liquid fuel supplied via direct injection, indirect injection,port injection and carburetor; common rail and unit injector systems;light (e.g. passenger car) and heavy duty (e.g. commercial truck)engines; and engines fuelled with hydrocarbon and non-hydrocarbon fuelsand mixtures thereof. The engines may be part of integrated emissionssystems incorporating such elements as; EGR systems; after-treatmentincluding three-way catalyst, oxidation catalyst, NOx absorbers andcatalysts, catalyzed and non-catalyzed particulate traps optionallyemploying fuel-borne catalyst; variable valve timing; and injectiontiming and rate shaping.

In one embodiment, the composition can comprise more than 3 wt % of aquaternary ammonium salt. In other embodiment, the composition cancomprise more than 4, or 5 wt %, or even 10 or 25 wt % of the quaternaryammonium salt.

In another embodiment, the composition can additionally comprise ahigher molecular weight quaternary ammonium salt. The higher molecularweight quaternary ammonium salt can comprise (a) a compound comprising(i) at least one tertiary amino group as described above, and (ii) ahydrocarbyl-substituent having a number average molecular weight of fromabout 500 to about 5000, or up to 2500, or up to 1500; and (b) aquaternizing agent suitable for converting the tertiary amino group of(a)(i) to a quaternary nitrogen, as described above. The highermolecular weight quaternary ammonium salts are more thoroughly describedin U.S. Pat. No. 7,951,211, issued May 31, 2011, and U.S. Pat. No.8,083,814, issued Dec. 27, 2011, and U.S. Publication Nos. 2008/0113890,published May 15, 2008, and 2011/0219674, published Sep. 15, 2011.

In certain embodiments, a composition comprising the quaternary ammoniumsalt can be employed in a diesel fuel. In a particular embodiment, thediesel fuel can be an ultra-low sulfur diesel fuel, meaning a dieselfuel having less than 30 ppm, or less than 20 ppm, or even less than 15ppm sulfur.

In an embodiment, a diesel fuel can contain the quaternary ammonium saltcomposition at from about 10 to about 500 ppm. In another embodiment,the quaternary ammonium salt composition can be present in a diesel fuelat from about 20 to about 250 ppm, or from about 30 to about 120 ppm.

The quaternary ammonium salt composition can be employed in a method ofminimizing creation of internal diesel injector deposits. The quaternaryammonium salt can also be employed to reduce the level of pre-existinginternal diesel injector deposits. In one embodiment, the quaternaryammonium salt composition can be employed in a method of minimizingcreation of internal diesel injector deposits while additionallyreducing the level of pre-existing internal diesel injector deposits.Any of the foregoing methods can comprise the steps of supplying to adiesel engine a diesel fuel composition comprising (A) diesel fuel; and(B) a composition of a quaternary ammonium salt as described herein. Inone embodiment, the method can include adding the diesel fuel andcomposition to a diesel engine comprising high pressure common raildiesel injectors.

As used herein, the term “hydrocarbyl substituent” or “hydrocarbylgroup” is used in its ordinary sense, which is well-known to thoseskilled in the art. Specifically, it refers to a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character. Examples of hydrocarbyl groupsinclude: hydrocarbon substituents, that is, aliphatic (e.g., alkyl oralkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, andaromatic-, aliphatic-, and alicyclic-substituted aromatic substituents,as well as cyclic substituents wherein the ring is completed throughanother portion of the molecule (e.g., two substituents together form aring); substituted hydrocarbon substituents, that is, substituentscontaining non-hydrocarbon groups which, in the context of thisinvention, do not alter the predominantly hydrocarbon nature of thesubstituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); heterosubstituents, that is, substituents which, while having a predominantlyhydrocarbon character, in the context of this invention, contain otherthan carbon in a ring or chain otherwise composed of carbon atoms.Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituentsas pyridyl, furyl, thienyl and imidazolyl. In general, no more than two,preferably no more than one, non-hydrocarbon substituent will be presentfor every ten carbon atoms in the hydrocarbyl group; typically, therewill be no non-hydrocarbon substituents in the hydrocarbyl group.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. For instance,metal ions (of, e.g., a detergent) can migrate to other acidic oranionic sites of other molecules. The products formed thereby, includingthe products formed upon employing the composition of the presentinvention in its intended use, may not be susceptible of easydescription. Nevertheless, all such modifications and reaction productsare included within the scope of the present invention; the presentinvention encompasses the composition prepared by admixing thecomponents described above.

EXAMPLES

The invention will be further illustrated by the following examples,which sets forth particularly advantageous embodiments. While theexamples are provided to illustrate the present invention, they are notintended to limit it.

Comparative Sample A:

Comparative Sample A is prepared from a mixture of succinic anhydrideprepared from 210 Mn polyisobutylene (350 grams) which is heated withstirring to 105° C. under a nitrogen atmosphere. Tetraethylpentamine(TEPA, 293.9 grams) is added slowly over approximately an hour,maintaining a batch temperature below 120° C. The reaction temperatureis increased to 175° C. and held for a further 4.5 hours. The resultingcompound is a TEPA succinimide.

Preparatory Sample 1

Preparatory Sample 1 is prepared from a mixture of succinic anhydrideprepared from 210 Mn polyisobutylene (800 grams) which is heated withstirring to 105° C. under a nitrogen atmosphere.Dimethylaminopropylamine (DMAPA, 289.9 grams) is added slowly over 95minutes maintaining batch temperature below 120° C. The reactiontemperature is increased to 150° C. and held for a further 3 hours. Theresulting compound is a DMAPA succinimide. 1109 grams of the resultingDMAPA succinimide is heated with propylene oxide (257.8 grams), aceticacid (177.75 grams) and 2-ethylhexanol (1156.5 grams) with stirring toreflux (˜80° C.) under a nitrogen atmosphere. The resulting compound isa propylene oxide quaternary ammonium salt.

Preparatory Sample 2

Preparatory Sample 2 is prepared from a mixture of 12-hydroxystearicacid (550.2 grams) which is heated with stirring to 100° C. under anitrogen atmosphere. Dimethylaminopropylamine (DMAPA, 205.5 grams) isadded slowly over 23 minutes and held at 100° C. for 3.5 hours, and thenheated to 110° C. and held for 17 hours, followed by a final heating to120° C. and held for 6.5 hours. The resulting compound is a fatty amide.The resultant fatty amide (534.6 grams), propylene oxide (149.57 grams),acetic acid (77.6 grams) and water (5.35 grams) are heated with stirringto reflux (˜80° C.) under a nitrogen atmosphere. The resulting compoundis a propylene oxide quaternary ammonium salt.

Examples 1 to 5 Fouling Test

The detergents are evaluated in a Direct Injection Fouling Test. Thetest is described as follows. An ultra-low sulfur diesel (<15 ppm S)plus the respective detergent* is filled into a John Deere 6068 Tier IIIPowertech 6.8 L 250 hp engine. The torque at test start is consistentlybetween 804 and 850 Nm. The engine is run at 95% load, or 95% of thepower capacity the engine can handle maintaining the engine at 1400 rpmbefore shutting itself down. The engine is maintained at 95% load, asmeasured by computer, for eight hours of runtime testing and then isshut down and allowed to soak for four hours. During operation, if the %load reaches the 98-99% range, the torque is adjusted downward until the% load comes back to 95%. The reverse process is employed when the loadreaches the 92-93% range. Torque measurements are taken every sixminutes along with exhaust temperature for each cylinder. After thetest, the injectors are disassembled and evaluated for cleanliness. Inevaluating effectiveness of the additives, all three of power loss,exhaust temperature change and injector sticking are considered. Minimalpower loss, temperature change and no injector sticking are desired. Theresults of the test are summarized in Table 1.

*Note: In Examples 1, 2 and 4 the active chemical is accompanied by atall oil fatty acid (TOFA) in the specified ratio of active chemical toTOFA.

TABLE 1 Results in the Fouling Test Torque Avg. Internal Dose lossExhaust Injector Example (ppm) (%) delta (C.) Deposits? 1 ComparativeSample 200 8.16% 10.1% Yes A + TOFA: 50/50 2 Comparative Sample 1006.15% 9.5% Yes A + TOFA: 50/50 3 Comparative Sample 50 could not 8.5%Yes A finish test 4 Preparatory Sample 200 0.04% 2.7% No 1 + TOFA: 50/505 Preparatory Sample 50 2.36% 2.0% No 2

The results of the test show that Comparative Sample A performs poorlyin the fouling test and that TOFA acts as a neutral dispersant. Incontrast, formulations using quaternary ammonium salt detergents of thepresent invention do not foul.

Example 6 Clean-Up Test

Given that Sample 1 has been shown not to foul, Sample 1 is tested forclean-up in a Direct Injection Clean-Up Test. The test is described asfollows. A mixture of an ultra-low sulfur diesel fuel and a foulingagent is filled into a John Deere 6068 Tier III Powertech 6.8 L 250 hpengine. The engine is run at 1400 rev/minute and 95% load. The engine ismaintained at these operating conditions for eight hours of runtimetesting and then is shut down and allowed to soak for four hours. Duringoperation, if the % load reaches the 98-99% range, the torque isadjusted downward until the % load comes back to 95%. The reverseprocess is employed when the load reaches the 92-93% range. After 32hours of runtime testing, the additive Preparatory Sample 1 is mixedwith the fuel mixture being injected into the engine. Further cycles areperformed until 49 hours of runtime testing is completed. Torquemeasurements are taken every six minutes along with the exhausttemperature of each cylinder. The change in exhaust temperature from 0to 32 hours, 32 to 49 hours, and over the entire test are summarized inTable 2, and the change in torque from 0 to 32 hours, 32 to 49 hours,and over the entire test are summarized in Table 3.

TABLE 2 Exhaust Temperature Results in the Clean-Up Test Exhaust deltaExhaust delta Exhaust delta Exhaust (C.) 0-32 hours (C.) 32-49 hours(C.) overall 1 −3.95% 2.14% 1.51% 2 −2.03% 1.53% 2.23% 3 −6.21% 3.76%0.77% 4 −3.01% 2.01% 0.60% 5 −3.96% 3.55% 0.50% 6 −1.81% 2.53% 1.43%

TABLE 3 Torque and Injector Results in the Clean-Up Test Torque Change(%) 0-32 hours 32-49 hours overall −10.82% 7.33% −0.29%

The results of the test show that quaternary ammonium salt detergents ofthe present invention can actually clean injectors.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.” Except where otherwise indicated, all numerical quantities inthe description specifying amounts or ratios of materials are on aweight basis. Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention canbe used together with ranges or amounts for any of the other elements.As used herein, the expression “consisting essentially of” permits theinclusion of substances that do not materially affect the basic andnovel characteristics of the composition under consideration.

1. A composition comprising a quaternary ammonium salt, wherein the quaternary ammonium salt comprises the reaction product of: a) a compound comprising (i) at least one tertiary amino group, and (ii) a hydrocarbyl-substituent derived from a hydrocarbon having a number average molecular weight of from about 100 to about 500; b) a quaternizing agent suitable for converting the tertiary amino group of compound (a) to a quaternary nitrogen.
 2. The composition of claim 1 wherein component a), the compound comprising at least one tertiary amino group and at least one hydrocarbyl-substituent, comprises: (I) the condensation product of an acylating agent substituted with the hydrocarbyl-substituent of a)ii) and a compound having an oxygen or nitrogen atom capable of condensing the acylating agent wherein the condensation product has at least one tertiary amino group; (II) an amine substituted with the hydrocarbyl-substituent of a)ii), wherein the amine has at least one tertiary amino group and the hydrocarbyl-substituent is a polyalkene-substituent; (III) a compound containing at least one hydrocarbyl-substituent of a)ii) and at least one tertiary amino group, wherein the hydrocarbyl-substituent is a polyester group; or (IV) any combination thereof.
 3. The composition of claim 1 wherein component a), the compound comprising at least one tertiary amino group, comprises the condensation product of a hydrocarbyl-substituted acylating agent and a compound having an oxygen or nitrogen atom capable of condensing with said acylating agent and further having at least one tertiary amino group; and wherein the hydrocarbyl-substituted acylating agent is polyisobutylene succinic anhydride and the compound having an oxygen or nitrogen atom capable of condensing with said acylating agent is dimethyl ethanolamine, diethyl ethanolamine, N,N-dimethyl-aminopropylamine, N,N-diethyl-aminopropylamine, N,N-dimethyl-aminoethylamine, and N,N-diethyl-aminoethylamine.
 4. The composition of claim 1 wherein component a), the compound comprising at least one tertiary amino group, comprises a polyalkene-substituted amine having at least one tertiary amino group; wherein the polyalkene substituent of the polyalkene-substituted amine is derived from polyisobutylene having a number average molecular weight of about 150 to about
 500. 5. The composition of claim 1 wherein component a), the compound comprising at least one tertiary amino group, comprises a polyester that is the reaction product of a fatty carboxylic acid containing at least one hydroxyl group and having a number average molecular weight of from about 100 to about 500 and a compound having an oxygen or nitrogen atom capable of condensing with said acid where said compound contains a tertiary amino group.
 6. The composition of claim 1, wherein the quaternary ammonium salt comprises a cation represented by the following formula:

wherein: R²¹ is a hydrocarbyl group containing from 1 to 3 carbon atoms; R²² is a hydrocarbyl group containing from 1 to 3 carbon atoms; R²³ is a hydrocarbylene group containing from 1 to 3 carbon atoms; R²⁴ is a hydrocarbyl group containing from 7 to about 36 carbon atoms; and X is a group derived from the quaternizing agent.
 7. The composition of claim 1, wherein the quaternary ammonium salt comprises a cation represented by the following formula:

wherein: R¹ is a hydrogen or a hydrocarbyl group containing from 1 to 4 carbon atoms; R² is a hydrocarbylene group containing from 1 to 3 carbon atoms; R³ is a hydrocarbyl group containing from 1 to 3 carbon atoms; R⁴ is a hydrocarbyl group containing from 1 to 3 carbon atoms; R⁵ is a hydrocarbylene group containing from 1 to 6 carbon atoms; R⁶ is a hydrogen or a hydrocarbyl group containing from 1 to 3 carbon atoms; n is a number from 1 to about 7; R⁷ is hydrogen, a hydrocarbonyl group containing from 1 to 3 carbon atoms, or a hydrocarbyl group containing from 1 to 3 carbon atoms; and X² is a group derived from the quaternizing agent.
 8. The composition of claim 1 wherein component b), the quaternizing agent suitable for converting the tertiary amino group of compound a) to a quaternary nitrogen, comprises: (a) dialkyl sulfates; (b) benzyl halides; (c) hydrocarbyl substituted carbonates; (d) hydrocarbyl epoxides; (e) esters of carboxylic acids and/or polycarboxylic acids; (f) any combination thereof; wherein the quaternizing agent may optionally be used in combination with an acid.
 9. The composition of claim 1, additionally comprising a quaternary ammonium salt, wherein the quaternary ammonium salt comprises the reaction product of: a) a compound comprising (i) at least one tertiary amino group, and (ii) a hydrocarbyl-substituent derived from a hydrocarbon having a number average molecular weight of from about 500 to about 5000; b) a quaternizing agent suitable for converting the tertiary amino group of compound (a) to a quaternary nitrogen
 10. A diesel fuel comprising the composition of claim
 1. 11. The diesel fuel of claim 10, wherein the diesel fuel is ultra-low sulfur diesel fuel.
 12. The diesel fuel of claim 10, wherein the quaternary ammonium salt is present from about 10 to about 500 ppm.
 13. A method of minimizing creation of internal diesel injector deposits while additionally reducing the level of pre-existing internal diesel injector deposits comprising the step of supplying to a diesel engine a diesel fuel composition comprising (A) diesel fuel; and (B) a composition according to claim
 1. 14. The method of claim 13 wherein the diesel engine comprises high pressure common rail diesel injectors. 